In an effort to mitigate the impact of pollution on the climate, tech giants Google and others have partnered with a startup called Terradot to use rocks to trap carbon dioxide. This approach is part of a strategy called enhanced rock weathering (ERW), which accelerates a natural process that breaks down rock and traps CO2 in water as bicarbonate.
The Deals
Google, H&M Group, and Salesforce have collectively agreed to pay Terradot $27 million to remove 90,000 tons of carbon dioxide from the atmosphere. This deal was brokered by Frontier, a carbon removal initiative led by Stripe, Google, Shopify, and McKinsey Sustainability. Separately, Google announced its own deal to purchase an additional 200,000 tons of carbon removal from Terradot.
The Technology
Enhanced rock weathering attempts to speed up the natural process of rock breakdown. Rainfall naturally "weathers" or breaks down rock, releasing calcium and magnesium and triggering a chemical reaction that traps CO2 in water as bicarbonate. Groundwater carrying this bicarbonate eventually makes its way to the ocean, which stores the carbon and keeps it out of the atmosphere.
Terradot’s approach involves crushing up rock and spreading it out over a large area, increasing the surface area of exposed rock that reacts with CO2. The company has partnered with Brazil’s agricultural research agency (EMBRAPA) to use this strategy on more than one million hectares of land in southern Brazil.
The Challenges
One of the challenges facing Terradot is measuring how much CO2 it actually manages to trap. Google admits that it’s hard to measure with precision, but says that deploying this approach widely in the real world will help develop highly rigorous measurement tools.
Terradot plans to take soil samples to assess how much CO2 is captured based on how the rock degrades over time. However, it’s harder to figure out how much calcium, magnesium, and bicarbonate makes it to the ocean to permanently sequester CO2. Fertilizer in the soil can potentially limit how much carbon is captured through enhanced rock weathering.
The Experts’ Perspective
Oliver Jagoutz, a professor of geology at MIT, says that this approach should be taken out of the academic world and into the industrial world. He acknowledges that there are uncertainties surrounding the technology, but believes that trying it out is better than not doing anything at all.
The Bigger Picture
Carbon dioxide removal encompasses a suite of strategies to take carbon dioxide out of the atmosphere. These technologies could potentially help slow climate change by trapping some of the pollution fossil fuels have already released into the atmosphere. However, switching to clean energy is still the most effective way to stop climate change.
Google’s carbon footprint has grown as it builds out energy-hungry AI data centers. The company has recently announced plans to help develop advanced nuclear reactors and new solar and wind farms to power its data centers with carbon pollution-free electricity.
The Verdict
Kanoff, the CEO of Terradot, says that carbon removal is not a substitute for emissions reductions at all. He believes that companies need both tools to combat climate change: aggressive emission reduction strategies and carbon removal technologies like ERW.
Comments
- Companies are exploring innovative ways to mitigate their impact on the environment.
- Enhanced rock weathering (ERW) is one such approach, which involves using rocks to trap CO2 in water as bicarbonate.
- Terradot’s technology has shown promise, but there are still uncertainties surrounding its effectiveness.
- The scientific community and industry experts must work together to refine this technology and develop more accurate measurement tools.
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